Biology

The correct answer is:

The frogs that were NOT exposed to the insecticides.

The control group is the group in the experiment that is not exposed to the independent variable (in this case, the insecticide). The control group serves as a baseline for comparison to see how the independent variable (insecticide exposure) affects the dependent variable (the health or survival of the frogs).

To clarify the other options:

A and B.The frogs that were exposed to 15 mL of insecticide and The frogs...